1. Field of the Invention
The present invention relates to agricultural vehicles, and, more particularly, to guidance assisted agricultural vehicles.
2. Description of the Related Art
Agricultural vehicles and implements are commonly used to perform various agricultural functions, such as tilling, planting, spraying, and fertilizing. As modern farming methods have become more competitive, it has become increasingly important that fields and agricultural products to be applied to the fields are used efficiently. To this end, agricultural functions applied to the fields, whether such agricultural function is tillage, seeding, or application of fertilizer or other chemicals, are carefully controlled in order to prevent gaps where the agricultural function is not applied, or overlaps where the agricultural function is applied more than once.
Agricultural vehicles commonly utilize control systems connected to position sensing technology, such as global positioning systems (GPS), to provide automatic guidance control in performing these various agricultural functions. The automatic guidance control systems are capable of steering the vehicle with a high degree of accuracy. The automatic guidance control systems often operate by creating at least one original base guidance line, called an “AB line,” and then generating an array of adjacent guidance lines to be followed by the agricultural vehicle in performing its function. These adjacent guidance lines, or swaths, depend not only on the geometry of the original AB guidance line, but also upon the physical characteristics and limitations of the agricultural vehicle and/or any towed agricultural implements. Such physical characteristics and limitations may include width, location of the implement with respect to the vehicle, and limitations of movement, such as minimum turning radius.
To produce the guidance lines, a user normally needs to drive the vehicle around a field and mark points as the vehicle is travelling to set the boundaries of the field. This not only requires resources such as time and fuel, but can require constant updating if the field boundaries change. Some automatic guidance control systems are capable of creating guidance lines based on points defining the field boundaries, but such systems produce swath patterns that leave gaps in the corners of the field. Further, users have to manually drive the vehicle in the corners to get the implement pulled by the vehicle exactly lined up in the corner of the field, which is an inconvenience. Even further, current systems require that the user selects which guidance line the automatic guidance control system follows, which might result in the user selecting a less than optimal guidance line for the vehicle's location in the field.
What is needed in the art is an automatic guidance control system that overcomes some of the disadvantages of known systems.